OAKLAND, Calif. (CBS) – The Oakland Zoo adopted two female tigers, Mia and Lola, from a roadside zoo that kept them in tiny, barren cages that had never been entered in years.

Zookeepers say it’s taken a month for Mia and Lola to become physically healthy again. Aside from the poor conditions the cats lived in, the private ownership of the tigers was completely legal in the state of Oklahoma, where they were being kept.

In 2003, federal law banned the sale and transport of big cats over state lines, but you can still be gifted a tiger or pay for one in cash without anyone being able to prove the transaction ever happened.

A new bill is heading to congress that would ban the private ownership of any big cat by anyone other than an accredited zoo or rescue facility and stops the use of big cats for entertainment purposes, like photos.